In the manufacture of display panels, the low temperature polysilicon technology provides the advantages of the low cost of manufactured products and the high electron mobility of devices, thereby increasingly becoming favored by manufacturers such as mobile phones and tablet's screens. However, because the use of low temperature polysilicon technology requires many layers of film and the structure of the layers of film is complex, the thin-film transistor array panel has significant difference in product height after the accumulation of several layers of film. In the subsequent cell process, it is likely to have a great impact on the alignment of the liquid crystals, which in turn causes product defects.